1. Field of Invention
This invention relates generally to a medical data card containing a summary of the medical history of the bearer germane to his existing medical condition, and more particularly to an internally-illuminated card of this type which is provided with front and rear transparencies affording a relatively large data capacity, the data carried thereby being legible and directly readable without the need for optical magnification.
2. Status of Prior Art
It is now known to provide an individual who has a serious medical condition with a medical data card in a plastic credit-card format. This card, which contains a summary of the individual's medical history to the extent that it is germane to his condition, is carried by the bearer at all times in a wallet or purse or elsewhere on the person where it is likely to be found should the person be searched.
The reason why certain individuals carry such medical data cards is that should they fall victim to a heart seizure, a pulmonary attack or to some other reaction which renders the bearer incoherent or unconscious, then the card may be consulted to expedite emergency medical treatment.
Under ordinary circumstances, should an individual who has a serious medical problem suffer from an attack when away from home, he will, if he is fortunate, be rushed to a nearby physician or to the emergency facility at the nearest hospital. But since the attending physician has not previously seen the patient, in the absence of a medical data card the doctor has no information regarding the medical history of the patient. This makes a rapid and accurate diagnosis difficult to carry out, and may in some instances lead to an erroneous judgment; for if the patient had been under medication, the prescribed drugs may so affect biological functions as to mask the patient's condition and mislead the diagnostician.
To assist an attending physician in an emergency situation of this type, some hospitals now issue a medical data card in a credit card format to be carried at all times by an outpatient, the card providing data pertinent to the medical condition of the patient, such as blood type, allergies and present medication.
In order to compress all necessary medical history data on a single card, existing cards of this type include a microfilm frame in which the data appears on a transparency in an optically-reduced scale, the frame being held within an aperture or window cut into the card.
Hence the data is not legible and directly readable and can only be read with the aid of an ophthalmoscope, an otoscope, a low-powered magnifier and whatever other optical magnification equipment is available at the facility at which the patient is being treated. Because not all physician's offices or hospital emergency rooms are equipped with optical magnification devices, one known type of medical data card produced by the U.S. Medicom Corporation provides a microfilm frame in which some of the significant or critical data is reproduced in a relatively large scale so that it can be read without optical assistance in an emergency situation, the remaining data being in a sharply-reduced scale.
The Destal U.S. Pat. No. 3,180,043, shows a card which is in a size that fits into a wallet and includes a microfilm frame mounted in a window, the frame carrying identification data in a reduced scale. A similar card is disclosed in the Cohen U.S. Pat. No. 3,792,542, in which the data appearing on the microfilm is critical medical data. In order to read microfilm data on a card, the Goss et al. U.S. Pat. No. 3,117,608, provides a foldable extension supporting a small magnifying lens.
The Brech U.S. Pat. No. 4,259,391, shows a plastic medical card in which some of the data is so printed as to be directly readable, most of the data being in a reduced scale on microfilm. The fact that medical data on microfilm is not legible is recognized in the Anderson U.S. Pat. No. 4,318,554, which notes that medical data cards of this type are not readable by the human eye without optical viewer equipment. The need for a microfilm reader is also acknowledged in the Domo U.S. Pat. No. 4,236,332, whose medical data card incorporates a microfilm frame.
In the Adrian U.S. Pat. Nos. 4,393,610 and 4,435,912, in order to avoid the need for a separate optical enlarger, the medical data card disclosed therein includes a foldable section provided with an enlarging lens, which section can be bent over to view the recorded microfilm data. As indicated by Adrian, in many cases the treating physician does not have any readily available means for reading microfilmed information and it is necessary, therefore, to couple such means to the card.
A good quality microfilm viewer adapted to enlarge a reduced-scale microfilm image on a medical data card and to project the magnified image on a viewing screen will afford highly readable data. But, unfortunately, a reader of this type is rarely available in an emergency facility. A small, low-cost lens coupled to a medical data card is, of course, better than nothing, but reading of the data with a small lens is quite difficult. Moreover, a card having a fold-in lens does not readily fit into the wallet in the manner of a credit card.
In the conventional medical data card, the microfilm frame held in an aperture in the card is a transparency in which all information is necessarily on one face thereof, thereby limiting the data capacity of the card to whatever information can be compressed by photographic reduction in the small area of the frame.
If one could be assured that in all instances a microfilm reader having a high-quality optical system would be available, then one could record all necessary or desirable data on the film slide in a sharply reduced scale without fear that the data, when magnified, would be so distorted optically that it would not be readable. But since in many instances an ordinary magnifying glass is all that is available, this limits the degree to which photographic reduction can be effected on a medical data card to provide readable results when the data is magnified.
In my above-identified copending patent application, there is disclosed a data medical card having front and rear transparencies or slides, each carrying medical data relevant to the bearer of the card in a directly readable scale, whereby the data is clearly legible without any optical magnification.
My copending application discloses a card which is of laminated construction and includes a core panel formed by front and rear plastic sections having light-transmitting properties, a metallized layer functioning as a double-faced mirror being sandwiched therebetween. Nested in the respective faces of the core sections are front and rear film transparencies containing medical data in a directly legible scale, the combined data affording the required summary. The long edges and one end of each core section are in a concave formation to define reflective convex terminations whereby light entering the remaining flat end is transmitted through the section is reflected by the convex terminations and by the mirror to provide multiple internal reflection, causing the light to illuminate the transparencies to enhance their readability.
The practical problem which arises with a medical card of the type disclosed in my copending case is that it is relatively expensive to manufacture. Moreover, while this card affords enhanced readability for both the front and rear transparencies, such enhancement is not necessary for a transparency which shows an electrocardiogram of the bearer in a reduced optical scale, for this electrocardiogram can be read with much less internal illumination. However, a transparency which contains relatively dense printed medical data in a reduced scale requires substantial internal illumination to be rendered readable.